Recently, there has been an outbreak of atypical pneumonia in Guangdong province in mainland China. Between November 2002 and March 2003, there were 792 reported cases with 31 fatalities (WHO. Severe Acute Respiratory Syndrome (SARS) Weekly Epidemiol Rec. 2003; 78: 86). In response to this crisis, the Hospital Authority in Hong Kong has increased the surveillance on patients with severe atypical pneumonia. In the course of this investigation, a number of clusters of health care workers with the disease were identified. In addition, there were clusters of pneumonia incidents among persons in close contact with those infected. The disease was unusual in its severity and its progression in spite of the antibiotic treatment typical for the bacterial pathogens that are known to be commonly associated with atypical pneumonia. The present inventors were one of the groups involved in the investigation of these patients. All tests for identifying commonly recognized viruses and bacteria were negative in these patients. The disease was given the acronym Severe Acute Respiratory Syndrome (“SARS”). The etiologic agent responsible for this disease was not known until the isolation of hSARS virus from the SARS patients by the present inventors as disclosed herein. Namely, the present invention discloses a novel human virus that has been isolated and identified from the patients suffering from SARS. The invention is useful in both clinical and scientific research applications.